OK - now for the results of Phase II.
I built a 48 LED series-parallel array in order to evaluate using 5mm LEDs vice buying
the light bars. The cost breakdown for this array is:
48ea 5mm white LED 10,000mcd = $5.50 (eBay)
12ea 33 ohm carbon 1/2 watt 5% resistors = $3.60 (Jameco electronics)
2ea 2.5in X 6in circuit boards = $8.00 (Radio Shack)
4ea PCB wire terminals = $3.00 (Radio Shack)
8ea Screws / Nuts / Stand-offs = $3.00 (Ace Hardware)
Wire = $0.20 (from spares)
Light fixture sheet metal = $5.50 (local A/C shop)
Total Cost = $28.80
So far so good - this approach is cheaper.
FYI the schematic is simple:
B+ -> LED1 -> LED2 -> LED3 -> LED4 -> Resistor -> GND
For the array I have 12 of these branch circuits in parallel. Measured current draw @12V is 121ma.
So how does it look? I'll try to post the pictures here:
Comparison of both units (uncovered)
48 LED Array (Covered)
Light Bars (Covered)
I think the Light Bar unit looks best. The light color is a bit warmer since it uses the SuperFlux LEDs vice the 5mm units. The light angle is much wider than the 48 LED array, due to the different type of LED. It also looks more like the flourescent fixture I'm hoping to replace.
I've also found a cheap
($3.00) current-limiting DC-DC converter that I've ordered and will evaluate.